I used 2 different types of wireless range extenders for a while, but they always had dropped connections, i always had to reset them a few times a week etc.... They were just problematic.(netgear and amped wireless)
So in a last ditch effort i bought an actiontec 500mbps powerline adapter and it's been super great. I've only had to unplug and replug it back in maybe once every 2 months. The speed is a little better than the wireless range extenders. I can get about 40mbps sustained on the actiontec powerline adapters, and only about 10-15mpbs on the wireless extenders. THe wireless extenders were useless for playing HD videos on my TV from my NAS server, but the actiontec adapters can play 720p no problem, and play some 1080p video without an issue. It does hiccup on some 1080p videos depending on the compression format.
If these zyxels can improve the speed and give double the speed, i'll be happy. Everyone mostly uses wireless range extenders, but powerline adapters are far more reliable in my experience.